Drill bit



W. E. WALKER Jan. 4, 1949.

DRILL BIT Filed Jun 15, 1944 Patented Jan. 4, 1949 UNITED STATES PATENT creme nitm mr' William E. Walker, nousnm, Tex. Application nine 15, 1944; steel no. 546,465

The present invention relates ful improvements in well drill v its primary object to provide, in the mamie hereinafter set fortnnovel means for autoin" cally indicating, while the tool is in o erational the hole, when said tool becomes worn and dull to the extent of requiring replacement.

Another very important object of the invention is to provide a drill bit of the aforementioned character which embodies unique means for releasing in the hole an indicating fluid or medium to be carried to the surface.

Other objects of the invention are to provide a drill bit of the character described which will be comparatively simple in durable, highly efficient andreliable in operation, compact and which maybe manufactured at low cost. I H N All of the foregoing and still further objects and advantages of the invention will? become apparent from a study of the followlngspecification, taken in connection with the accom panying drawing, wherein like characters of reference designate corresponding parts through out the several views, and wherein:

Figure 1 is an elevational view of a drill bit constructed in accordance with: the present invention, a portion being broken away in section.

Figure 2 is a vertical sectional view through one of the blades.

Figure 3 is a diagrammatic view of the electric circuit.

Figure 4 is an elevational modification. a

Figure 5 is a view in horizontal section; taken substantially on theline 5-5 of Figure 4.

Figure 6 is a view in sideelevation of one of the blades of the modification t a Figure 7 is a fragmentary view in elevation of another form of the invention with a portion broken away in vertical section.

Referring now to the drawing in detail, it will be seen that reference character I designates a holder having mounted thereon a pair of blades 2 having cutting edges 3. The holder I has formed therein a plurality of chambers 4. Ducts 5 extend from intermediate portions of the chambers 4 through the holder 1 and terminate in closed ends adjacent the cutting edges 3 of the blades 2.

The chambers 4 are for the reception of electric batteries 6. Also mounted in the chambers 4 outwardly of the batteries 6 are frangible containers 7. A partition 8 divides the containers 1 into a pair of chambers, one of which is filled to new and use;

view, showing a bits and has for onstruction, strong,

' an 6* of the rawing, coll r n t me 2 Claims. (01. ass-r1) with a suitableindicating nine 9 having' a'; dist tin'guishing color, odor, etc. The other chamber is for the reception of an ex losive andhas mounted therein an electric heating; elemnt Hi. The elements; 10' are electrically con ected to the batteris s which in turn; are grounded to the holder l Insulated conductor wires H are mounted in the ducts Sand are connected tothe elements 10. i M

It is thought that the manner in which the invention asthus far described func'tions will be readily appa-rent in a general way from a consideration of the foregoing. Briefly when the cutting edges 3 of the blades 2 become dull and worn to the point of needing replacement, the insulation is worn from the conductor wires H and said wires are thus exposed and grounded. In this mannerthe' electric circuits which include the heating elements- |il areco1npleted and said elementsare" heated. The eieme'ms m ignitethe explosive which ex pels the indicating mediums from the chambers mintothe holeto be carried to the surface.

In themodifi'cation illustrated in Figuresi, 5 i2: is m unted on the usualstm portion F3 or the holder I. The collar l2 has formed therein" wells or chambers w the aforaid chambers 4f for the reception of thebattries 6:, the containers 1 and the'hea'tihg elements 10* therein, etc. Tubular containers [5 of suitable-metal aresecured vertically by welding or otherwiseon either the front or back faces of the blades 21 The tubular (1on miner t en los ae" end pbrtion r insulated e et es t h i 1 their ine e s a e: trf caf lly connected to the elements Ill" in the am I1 a u M In i fer fi t. WKI Y 1llP I f s. 9.? we blades 2"bie'c6hl dull and wear 0esentient-1v; the adjacent end portions of the tubular containers I5 and the corresponding end portions of the insulation on the conductor Wires l6 are also worn off. In this manner the conductor wires l6 are exposed for grounding and completing the electric circuit, thereby heating the elements ID for igniting the explosives and ejecting the indicating mediums 9 in the containers M from the collar l2 to be carried to the surface.

In the modification of Figure 7 of the drawing collapsible bellows type containers IT, for the reception of a fluid 18, are mounted in the chambers I 4. Exposed tubes 9 are mounted on the front or back faces of the blades 2 and are connected to the containers 11, said tubes comprising closed ends located adjacent the cutting 3 of said blades. Covers I9 are provided I4 in this form of the invention. The covers I9 are provided with suitable vents in order that the chambers are internally exposed to all external pressures, thereby making it possible toutilize the reactive spring pressure on the bellows-like containers IT as the difierential force with which to eject the indicating medium. Coiled springs are mounted under tension between the covers I9 and the collapsible containers IT to give the necessary fluid ejecting pressure on the containers I! when occasion requires.

In operation of the embodiment of Figure 7 of the drawing, the closed ends of the tubes I9 are worn ofi When the cutting edges 3 of the blades 2 become sufilciently dull and worn to require replacement. When this occurs the containers II are collapsed by the coil springs 20 for ejecting the fluid I8 therefrom through the tubes I9 into the hole to becarried to the surface.

It is believed that the many advantages of a drill bit constructed in accordance with the present invention will be readily understood and although preferred embodiments are as illustrated and described, it is to be understood that further modifications and changes in the details of construction may be resorted to which fall within the scope of the invention as claimed.

What I claim is:

1. In a drill bit including cutting edges, a closed container mounted on saidbit and cont ainingv an indicating material, there being a communicable passage extending from said container and terminating at a point within said cutting edges, an explosive cooperatively associated with said container, a source of electric current carried by said bit and grounded to the latter, an ignitible element operatively associated with said explosive and electrically connected to said source, and a conductor insulated from said bit extending through said passage and having one end connected to said ignitible element and its other end positioned in the termination point of said passage, whereby wearing away of the cuttingedges to an extent such as to remove the insulation from the end of the conductor complemental thereto and bring said conductor into electrical contact with said bit causes the ignitible element to ignite the explosive and upon the ignition of the explosive to open the container and discharge the indicating material into the surrounding hole.

2. In a drill bit including cutting edges, a closed container mounted on said bit and containing an indicating material, there being a communicable passage extending from said container and terminating at apoint within said cutting edges, an explosive cooperatively associated with said edges for the chambers container, 9. source of electric current grounded to said bit and electrically connected to said explosive, and a conductor insulated from said bit extending through said passage and having one end connected to said source and its other end positioned in the termination point of said passage, whereby Wearing away of the cutting edges to an extent such as to remove the insulation from the end of the conductor complemental thereto and bring said conductor into electrical contact with said bit causes the ignitible element to ignite the explosive and upon ignition of the explosive to open the container and discharge the indicating material into the surrounding hole.

3. In a drill bit comprising a holder, blades provided with cutting edges mounted on said holder, a plurality of chambers in said holder, each of said chambers having an electric battery and a frangible container containing an indicating material mounted in spaced relation therein, an explosive interposed between said frangible container and said battery and cooperatively tery being grounded to said holder, an ignitible element op'eratively associated, with said container and electrically connected to said battery, ducts extending from each of said chambers and terminating at a point within the cutting edges of said blades, and conductor wires insulated from said holder extending through each of said ducts, each of said wires having one end thereof connected to said ignitible element and'the other end positioned in the termination point of said duct Whereby wearing away of cutting edges to an extent such as to remove the insulation from the ends of the conductor wires complemental thereto and bringing said conductor wires into electrical contact with said holder causes the ignitible. element to ignite the explosive and upon ignition of the explosive to open the container and discharge the indicating material into the surrounding hole.

WILLIAM E. WALKER.

REFERENCES orrnp The following references are of record in the file of this patent:

UNITED STATES PATENT Date associated with said container, said bat-i 

